Angle recognition algorithm based on discrete series data of object-boundary in polar coordinate

In computer vision applications on automation production lines, rotary angle of an object is often required to be calculated in the procedure of image processing. An angle recognition algorithm based on discrete array of object-boundary in polar coordinate is proposed. Firstly, calculate the object's center point and establish the polar coordinate using the object's center as the pole point. Then get the object's boundary through image processing method and discretize it according to the rule that they have the same central angles in the polar coordinate. Match the discretized array with that of the template image by step method and a rough rotary angle is obtained. Lastly, Liner interpolation method is used to get the exact solution. Practical matching experiments show that the method is simple and effective.